Transient absorption and fluorescence measurements of polymer liquids and gels
Wojciech Gadomski
Herewith we present the optical characteristics of three polymer liquids, based on PPV derivatives, which are used as a matrix for semiconductor quantum dots PbS, both in the liquid and in the gel state. The transient fluorescence measurements of polymers exhibit strong dependence of the exciton lifetimes in polymers on the concentration of the nanocrystals. It appears that the fluorescence lifetimes increase with the increase of the PbS nanocrystal concentration, which suggests that the surface interaction of polymer with quantum dot stabilizes the emerging exciton. The transient absorption measurements, in turn, allow to establish how the nanocrystal interaction with the matrix influences the lifetime of the quantum dot excited state and the flow of the charge from quantum dot to the polymer.